Speciation is the process by which an interbreeding population becomes divided into reproductively isolated groups. The long-term research goal in our laboratory is to test the hypothesis that the first steps toward postzygotic reproductive isolation are due to the evolution of sex-ratio meiotic drive systems. Sex- ratio meiotic drive is a phenomenon of non-Mendelian segregation manifested by genetic conflicts between sex chromosomes and autosomes. In the proposed research, we shall characterize genes involved in meiotic drive and/or hybrid male sterility. First, we will study the Winter sex-ratio for the molecular mechanisms involved for this system through small RNA profiling and transgenics. Second, we will study the Durham sex-ratio to characterize the hybrid male sterility loci that are either member of or interacting with this sex-ratio system. In the end, we expect to determine the molecular and evolutionary link between meiotic drive and speciation. PUBLIC HEALTH RELEVANCE: Speciation is the process by which an interbreeding population becomes divided into reproductively isolated groups. We propose to determine the molecular and evolutionary link between meiotic drive, a form of genetic conflicts within a genome, and speciation.